Fig. 5 presents compressive strength results of both NC and MCs
after 84 days immersion in Na2SO4. Unlike in the previous assessments
where initial strengths among all specimens were observed
to be low due to immediate transfer of specimens from moulds to
the aggressive curing medium, in this case, initial strengths were
relatively high since specimens were cured for 28 days before
immersion into the Na2SO4. During the 84 days, all categories of
specimens gain strengths at the beginning but suffer strength loss
towards the end. However, NC suffers the highest strength loss. In
fact, NC with second highest strength value ended up as the least
strength among all.